Hi all,
I've got a 2018 Escalade ESV (6.2L L86 w/ 10l80) that I recently had an AFM delete done on (Texas Speed kit with the base/stock cam, so no change in cam profile). I'm about a 6/10 driveway mechanic but this was a bit too detailed a surgery for my taste, so I farmed it out to my regular mechanic. Joe was rushing to get it done before vacation and is now gone for two weeks. After I picked it up, the CEL came on after a couple of miles and it's throwing a P219B (air/fuel ratio imbalance, bank 2). Both long term fuel trims are steeply negative, with bank 2 running about 5 to 7% lower than bank 1.
One thing worth mentioning on the tune side: I loaded a Trifecta tune about 20k miles ago, right after I bought the truck, specifically to disable AFM in software. That same tune is still on the truck. Joe did not touch the tune during the delete, so it's running the original AFM-disable Trifecta file on top of the fresh delete hardware.
I'm driving it sparingly until Joe gets back but would like an idea of what I'm working with before then. He's convinced we're looking at a bad fuel injector that just happened to go south right after the delete (color me slightly skeptical, but he's a good guy and I'm sure he'll take care of me either way).
When I logged the parameters and looked at the data, one thing that came up was whether the truck was properly re-tuned after the physical delete. My assumption going in was that with the base cam, the only tuning needed for an AFM delete is just turning AFM off, which I'd already done in software. But I'm now wondering if the truck actually needs a proper re-tune for the delete hardware and that's what's driving the P219B.
So my main questions for the group:
Do I need a dedicated re-tune after a physical AFM delete even if I kept the stock cam, given the truck is still running the same software AFM-disable tune from 20k miles ago?
Does a bilateral steeply negative LTFT with a 5 to 7% bank split point more toward a tune issue or toward Joe's bad-injector theory?
And of course, any other thoughts on what could be going on here are very welcome.
TIA
You heard of chevron fuel? They have the additive. I trust other brands do to. I let my Hyundai service writer talk me into injecting cleaner on my wife’s Genesis. It was running fine no issues. After nothing was changed. How could it? It was fine before hand. I guess if it makes people feel better. I agree about buying fuel where the most traffic is.
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